Dual Core CPU's really matter?

I bought a FX55 single core 199us, last year's big thing, to see if dual core cpu's matter. Point being, there is a an AMD patch link for dual core cpus in the Company of Heros readme. Also stated is to turn off the second cpu in Dark Messiah and COD to run smoother. I don't think dual core cpu's do squat in games yet. Anyone really notice a difference except synthetic bench?

No, instead, because I chose to use XP 64 to enhance my dual core system. I find I have plenty of problems with things that don't run properly!!

Actually there was quite large discussion in the game developers community around the multicore things recently. It was fun to read. The discussion was lead by Gabe Newell. You may start here

http://techreport.com/onearticle.x/11237

I believe the discussion was more intensive based on recent 4 core CPUs release which clearly says "we are shifting from higher frequency to more cores".
As you can see, the actual support for multicore CPU's in games is poor at best. There are only few titles that (sometimes after applying specific patches) really use multiple CPUs (cores) by implementing so called coarse threading (specifically loading some independant tasks to the second core). So the real support is still matter of few years. By "real support" I mean inteligently load the cores with work to keep the load at least partially balanced.

@Corwin -- Tom's Hardware tested WinXP 64 a while back. Their conclusion was that it performs exactly as fast as vanilla WinXP. I.e., the only advantage is that you can address more memory. The disadvantages are that lots of drivers and programs are borked. IOW, don't do it unless you really need more than 4GB of RAM.

It's a little late to tell me that after I installed it earlier this year!!